If you are someone who is into hunting or is into precision shooting, chances are that this particular question may be something you’ve run into.
A wrongfully mounted scope can not only severely kneecap the gun’s accuracy but also affect the comfort and ease of use of the whole gun itself. Either way, measuring the right scope height is one of the most basic things you can do to maximize your gun’s potential.
Covered below is a comprehensive guide as to how to measure scope height and explanations are given where they are necessary.
Why scope Height is Important?
The way a scope is mounted on to the rifle can affect the gun’s efficacy in many ways and it’s not just limited to the gun’s accuracy.
Fit your scope with rings that put it excessively high and you may not get a decent cheek weld, making both your accuracy and comfort suffer. Try and use rings that put the scope too low, and your extension may hit or rub along the barrel before it lays on the front scope ring.
An improper elevation of the scope ring can literally force you to hold your weapon in an unnatural/uneasy position. Consequently, this can lead you to suffer from recoil, bad aim, and a ton of other unwanted damages.
Additionally, the height of a scope can also determine its longevity, for instance, if the scope is mounted too high, it’ll experience higher than normal torque & g-force when going through recoil. This can eventually wear out or break the scope.
Measuring scope height – Step-by-Step guide
There are a couple of great methods that are generally used to find the right scope height for your gun, though some are more accurate than others.
The Easiest Method (Slightly Less Accurate)
- To get a rough measurement of the scope height, just take the scope’s objective lens diameter (usually measured in millimeters), add 2-4mm depending on the thickness of the scope’s body, and divide the result by two to estimate the scope height.
- If you want a bit more accurate measurement, you can just calculate the diameter of the scope body at the objective lens and divide that number by half. To convert the inches to millimeters, multiply your measurement by 25.4.
- This should give you a pretty accurate measurement of what your gun’s ideal scope is gonna be, it should be more than enough for ensuring good accuracy.
The Best Method
Offering superior accuracy, this particular method is especially useful for calculating scope height on bolt action and open sight rifles, like the ones hunters & ranchers typically use.
- First, measure the diameter of the bolt and divide that in half
- Measure the diameter of the riflescopes tube and then divide that in half
- Measure how far it is from the top of the rifle bolt to the bottom of the riflescope
- Add the answers together and voila! That’s your scope height.
How this calculation will work with a real rifle scope
Model in question: a Remington 700 .308 with a Leupold Mark 4 M1 tactical riflescope measuring 6.5-20X50mm
- The bolt measurement is .696” hence its 696”/2 = .348”
- The scope tube measurement is 30mm hence it’s 1.181/2 = 591″
- Distance from the top of the rifle to the base of the scope = .75”
Add up all the numbers you got from all three measurements: .348” + .591” + .75 = 1.68” – this is your scope height. Do keep in mind to account for the tube body’s shell thickness too if you want a high precision figure.
Choosing the right rings
Once you know what’s your scope height is, you will be clear on the minimum height that the centreline of the scope must need to sit above the receiver. Now all that is left is to purchase the smallest ring and base combo that’s higher than this measurement.
For example, if your scope height is 22mm exactly, you can use any ring and base suite that’s higher than 22mm and get the right aim.
Depending on the manufacture, some gauge ring height from the inner ring rim to the base. If this is the case, you need to add the following values to them according to their scope height.
- For a 60mm scope, add 0.5 inches
- For a 30mm scope, add about 0.6 inches (0.59 to be exact)
- For a 35mm scope, add 0.68 inches
Only by choosing the right rings will the hunt for your perfect scope height will be over. In a way, they complete each other, thus giving you the perfect aim.
Researched and written by the American Gun Facts team. We are a group of Americans dedicated to providing factual information on firearms and fighting back against attempts to weaken or discard the Second Amendment. We write on topics ranging from firearm statistics, news, reviews, and more! AGF has been featured in the New York Times, NBC, MSN, Time, & many other publications.